EP0259924A2 - A device at a spring brake actuator - Google Patents
A device at a spring brake actuator Download PDFInfo
- Publication number
- EP0259924A2 EP0259924A2 EP87201662A EP87201662A EP0259924A2 EP 0259924 A2 EP0259924 A2 EP 0259924A2 EP 87201662 A EP87201662 A EP 87201662A EP 87201662 A EP87201662 A EP 87201662A EP 0259924 A2 EP0259924 A2 EP 0259924A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- locking
- piston rod
- yoke
- ring
- spring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
- B60T17/08—Brake cylinders other than ultimate actuators
- B60T17/16—Locking of brake cylinders
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
- B60T17/08—Brake cylinders other than ultimate actuators
- B60T17/085—Spring loaded brake actuators
- B60T17/086—Spring loaded brake actuators with emergency release device
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
- B60T17/08—Brake cylinders other than ultimate actuators
- B60T17/083—Combination of service brake actuators with spring loaded brake actuators
Definitions
- This invention relates to a device for discontinuing and automatically restoring the operational function of a spring brake actuator, comprising a piston with a piston rod and a spring actuating the piston and piston rod in a working direction for brake application at falling brake fluid pressure on the piston, a slitted, resilient locking ring of the circlip type being arranged in grooves facing each other in the piston rod and a piston rod sleeve coaxial therewith.
- a spring brake actuator is normally utilized for parking or emergency brake purposes.
- a device of the kind described above - for obtaining a so called quick-release - is needed for the case that no fluid pressure is available for compressing the spring and thus for releasing the brakes and that the vehicle - preferably a rail vehicle - on which the actuator is mounted must be moved.
- the force transmitting path in the actuator from the spring to the member delivering its force from the actuator, in this case between the piston rod and the piston rod sleeve must be broken by external, manual action but must be restored automatically at the return of brake fluid pressure for compressing the spring.
- the purpose of the invention is to attain a device of the kind described above which is sturdy, reliable and cheap and which further does not require much space and is externally operable with moderate effort.
- externally operable, spring-biased control means at the slit of the locking ring are movable between a first position, in which the locking ring is constrained to rest in both of the grooves, so that the piston rod and piston rod sleeve are locked together, and a second position, in which the locking ring is free to be forced completely into one of the grooves, which is at least as deep as the thickness of the ring, so that the piston rod and piston rod sleeve are free to move independently of each other.
- the discontinuation is hereby obtained by manually operating the control means, which are then spring-biased back for the automatic restoration of the device.
- the ring For the purpose of transferring the locking ring to the groove being at least as deep as the thickness of the ring, when the control means have been operated, the ring has a tapered side surface cooperating with a corresponding side surface of the other groove.
- control means are characterised in that a locking yoke, which is movable radially relative to the locking ring and can engage heads at the respective ends of the ring for keeping them together, and a locking cube, which is movable substantially perpendicularly to the yoke and will lock the yoke in said engaging condition when placed above the yoke, are arranged in a compartment in a piston rod flange.
- the height of the compartment is such that the cube is supported by the end wall thereof in said yoke locking position.
- the manual operation of the locking cube is preferably attained in that a control rod attached to the locking cube extends out of the piston rod flange, a compression spring being arranged around the control rod for accomplishing a spring bias on the cube into its yoke locking position.
- the locking yoke and the locking cube are provided with corresponding bevelled or slanted surfaces.
- Fig. 1 is a side view, partly in section, of a combined brake unit and spring brake actuator incorporating the invention
- Fig. 1A is an enlarged part of Fig. 1 showing the most important details
- Fig. 2 is a cross-sectional view along the line II-II in Fig. 1, Figs. 3 and 4 in a front view and a cross-sectional view, respectively, schematically illustrate a second embodiment of the invention
- Figs. 5 and 6 in a front view and a cross-sectional view, respectively, schematically illustrate a third embodiment of the invention.
- FIG. 1 A combined rail vehicle brake unit and spring brake actuator is shown in Fig. 1.
- a brake piston 1 is axially movable in a brake unit cylinder comprising a housing 2 and a bottom 3.
- a piston return spring 4 is as usual arranged between the piston 1 and the bottom 3.
- a tube-shaped, stationary member 5 is integral with the bottom 3 and houses a slack adjuster (not shown) of any conventional kind.
- An outgoing force-transmitting part 6 may be regarded as connected to the piston 1.
- a spring brake actuator is combined with the brake unit so far described.
- the actuator has a cylinder-shaped housing 7 provided with brackets 8 for the mounting of the combined brake unit and actuator to a suitable part of a rail vehicle underframe (not shown).
- the two housings 2 and 7 are firmly joined together and with the bottom 3 in a conventional way not described.
- a piston 9 with a piston rod 10 is axially movable in the cylinder- shaped housing 7.
- the piston 9 is provided with a sealing 11, and a further sealing 12 is arranged in the housing 7 against the piston rod 10.
- a forceful compression spring 13 of the helical type is arranged around the piston rod 10 between the housing 7 and a flange 10 ⁇ on the piston rod 10.
- the piston rod 10 is tubular and slidable on the cylindrical, stationary member 5.
- a piston rod sleeve 14 is normally functionally connected to the piston rod 10 by means of a resilient locking ring 15 in two annular grooves 16, 17 facing each other in the piston rod 10 and the sleeve 14, respectively.
- the function of the locking ring 15 will be described in further detail below.
- the sleeve 14 is partly guided for axial movements on the stationary member 5 but also within the piston rod 10.
- the force from the spring 13 transferred via the piston rod 10, the locking ring 15 and the piston rod sleeve 14 is transmitted to the force-transmitting part 6 by means of a spring ring 18 arranged in an annular groove in the part 6.
- Fig. 1 both the brake unit and the spring brake actuator are shown in their respective inactive conditions.
- the spring brake actuator this means that the spring 13 is held compressed by brake fluid pressure acting to the right in Fig. 1 on the piston 9. It is obvious that if this fluid pressure is lowered, the force of the spring 13 will act on the outgoing force-transmitting part 6 via the spring ring 18, provided that the locking ring 15 is in its shown position axially locking the two members 10 and 14 together.
- the brake unit itself can apply a brake force (by fluid pressure acting on the piston 1) via the force-transmitting part 6 without involving the spring brake actuator.
- the locking ring 15 is slitted (or in other words of the circlip type), as appears in Fig. 2, and can be forced to expand radially from its rest position shown in Figs. 1 and 2. This expanding force is accomplished by a tapered side surface cooperating with a corresponding tapered side surface of the groove 17 as most clearly shown in Fig. 1A.
- the depth of the groove 16 in the piston rod 10 is at least as great as the thickness or height of the locking ring 15. Accordingly the ring 15 - if forced and allowed to expand - can be fully accomodated in said groove unlocking the connection with the piston rod sleeve 14, which thus can move independently of the piston rod 10.
- the locking ring 15 is provided with a head 15 ⁇ having an oblique or wedge-shaped external surface.
- the heads 15 ⁇ extend into a compartment 20 in the piston rod flange 10 ⁇ .
- a locking yoke 21 is arranged in this compartment 20 as well as a locking cube 22 above the yoke against the top wall of the compartment.
- the upper surface of the yoke 21 and the lower surface of the cube 22 are correspondingly oblique or wedge-shaped, as most clearly appears in Fig. 3.
- the wedge angle is comparatively small, as will be further described below.
- the total height of the compartment 20 is such that the yoke 21 - having inner surfaces conforming to the outer surfaces of the locking ring heads 15 ⁇ - is held down over the heads, when the cube 22 is right over the yoke as illustrated.
- the yoke 21 is guided for movements radially relative to the locking ring 15.
- the cube 22 is movable perpendicularly thereto and is attached to a control rod 23 extending out of the piston rod flange 10 ⁇ , in which it is situated.
- a ring-shaped control lever 24 is attached in an oblong hole in the end of the rod 23 .
- the control rod 23 and thus the locking cube 22 can be moved to the right in Fig. 2 by depressing the control lever 24, so that the locking yoke 21 can move radially upwards in the compartment 20 leaving its engagement with the locking ring heads 15 ⁇ .
- the locking ring 15 can be forced to expand radially into the piston rod groove 16 by its tapered side, thus allowing free relative axial movements between the piston rod 10 and the piston rod sleeve 14, which otherwise are locked together by the locking ring 15.
- a return spring 25 of the helical compression type is arranged around the control rod 23 and exerts a biasing force to the left in Fig. 2 on the locking cube 22 for again placing it in locking position above the locking yoke 21.
- the aim of the mechanism having as its main component the locking ring 15 controlled by the parts 21-25 is to allow a discontinuation of the force transmission from the spring 13 to the part 6 via the sleeve 14 in spite of the fact that there is no fluid pressure available for compressing the spring 13 by pushing the spring brake piston 9 to the right in Fig.1.
- a situation occurs when worn-out brake pads shall be replaced or when a parking braked vehicle equipped with a brake unit integrated with a spring brake actuator as shown in Fig. 1 is to be moved in the absence of brake fluid pressure.
- Step 1 is the transformation of the axial force from the spring 13 acting on the locking ring 15 to a reduced radial force through the locking ring wedge surface.
- Step 2 is the transformation of the radial force in the locking ring 15 to a tangential force in the locking ring heads 15 ⁇ ; the force reduction obtained is constant and only depending on the geometrical relations.
- Step 3 is the transformation of the tangential force to a radial force on the locking yoke 21 obtained through the cooperating outer and inner surfaces, respectively, in the heads 15 ⁇ and in the yoke 21.
- Step 4 is the transformation of the force in the radial or upwards direction in the yoke 21 to an axial force in the control rod 23 by the cooperating sloping surfaces on top of the yoke 21 and on the lower side of the locking cube 22, respectively.
- a locking ring 30 (completely corresponding to the locking ring 15 in the first embodiment) is arranged in two circumferential grooves 31 and 32 in two spring brake actuator parts 33 and 34, respectively.
- the locking ring 30 is slitted and has a bias to the position shown in Figs. 3 and 4. By a wedged side it will be subjected to a force biasing it radially into the groove 31 in the part 33 if not held in position. This is performed by a circumferential control latch 35, which is pivotally mounted at a fixed point 36. The pivotal movement in the direction of the arrow in Fig. 3 is limited by a fixed pin 37 and a corresponding recess in the latch 35.
- Two notches are provided in the latch 35: a first one for a first head 38 on the latch and a second one for a second head 39 thereon.
- the first head 38 is big enough never to leave its latch notch, when the latch 35 is manually transferred in the direction of the arrow, whereas the second head 39 in the corresponding situation will be free from the latch 35, so that the locking ring 30 can expand radially into the groove 31 and set parts 33 and 34 free to move independently relative each other.
- the locking function of the locking ring 30 will be restored automatically, provided that a return spring force is exerted on the locking ring 35 in the clockwise direction as viewed in Fig. 3.
- the spring brake actuator shown and described is combined with a brake unit, but it is to be understood that the invention is equally applicable to a spring brake actuator used alone, also as service brake actuator. The invention is likewise applicable to a spring brake actuator used for other purposes than on rail vehicles.
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- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Braking Arrangements (AREA)
- Braking Systems And Boosters (AREA)
- Braking Elements And Transmission Devices (AREA)
- Control Of Driving Devices And Active Controlling Of Vehicle (AREA)
Abstract
Description
- This invention relates to a device for discontinuing and automatically restoring the operational function of a spring brake actuator, comprising a piston with a piston rod and a spring actuating the piston and piston rod in a working direction for brake application at falling brake fluid pressure on the piston, a slitted, resilient locking ring of the circlip type being arranged in grooves facing each other in the piston rod and a piston rod sleeve coaxial therewith.
- A spring brake actuator is normally utilized for parking or emergency brake purposes.
- A device of the kind described above - for obtaining a so called quick-release - is needed for the case that no fluid pressure is available for compressing the spring and thus for releasing the brakes and that the vehicle - preferably a rail vehicle - on which the actuator is mounted must be moved. Thus, the force transmitting path in the actuator from the spring to the member delivering its force from the actuator, in this case between the piston rod and the piston rod sleeve, must be broken by external, manual action but must be restored automatically at the return of brake fluid pressure for compressing the spring.
- It is already known to employ a locking ring or spring ring for the general purpose set out above. In the design shown in the Swedish Patent Specification No. 7314474-3, especially Figs. 4-6, the use of a spring ring is disclosed, although its purpose is different, namely to hold the actuator spring compressed in the absence of fluid pressure and automatically to release it at the return thereof.
- However, in this design the means for controlling the spring ring, based on the use of balls exerting an expanding force on the ring, are less developed and have certain disadvantages.
- The purpose of the invention is to attain a device of the kind described above which is sturdy, reliable and cheap and which further does not require much space and is externally operable with moderate effort.
- This is according to the invention attained in that externally operable, spring-biased control means at the slit of the locking ring are movable between a first position, in which the locking ring is constrained to rest in both of the grooves, so that the piston rod and piston rod sleeve are locked together, and a second position, in which the locking ring is free to be forced completely into one of the grooves, which is at least as deep as the thickness of the ring, so that the piston rod and piston rod sleeve are free to move independently of each other.
- The discontinuation is hereby obtained by manually operating the control means, which are then spring-biased back for the automatic restoration of the device.
- For the purpose of transferring the locking ring to the groove being at least as deep as the thickness of the ring, when the control means have been operated, the ring has a tapered side surface cooperating with a corresponding side surface of the other groove.
- In a practical and preferred embodiment the control means are characterised in that a locking yoke, which is movable radially relative to the locking ring and can engage heads at the respective ends of the ring for keeping them together, and a locking cube, which is movable substantially perpendicularly to the yoke and will lock the yoke in said engaging condition when placed above the yoke, are arranged in a compartment in a piston rod flange.
- In order to take care of the force on the locking cube originating from the locking ring, the height of the compartment is such that the cube is supported by the end wall thereof in said yoke locking position.
- The manual operation of the locking cube is preferably attained in that a control rod attached to the locking cube extends out of the piston rod flange, a compression spring being arranged around the control rod for accomplishing a spring bias on the cube into its yoke locking position.
- As has already been mentioned, it is important to obtain a force-reduction of the manually operable member, i.e. the control rod. One such force-reduction step is achieved by the tapered side surface of the locking ring, as mentioned above. Further reductions to a desired level are attained in that on one hand the outer surfaces of the locking ring heads and the corresponding inner surfaces of the locking yoke and on the other hand the upper surface of the yoke and the corresponding lower surface of the locking cube are oblique or wedge-shaped.
- For the purpose of enabling the compression spring around the control rod to move the locking cube back into position above the locking yoke, or in other words for the automatic restoration of the operational function of the spring brake actuator, at the return of fluid pressure for compressing the powerful spring in the actuator, the locking yoke and the locking cube are provided with corresponding bevelled or slanted surfaces.
- The invention will be described in further detail below reference being made to the accompanying drawings, in which Fig. 1 is a side view, partly in section, of a combined brake unit and spring brake actuator incorporating the invention, Fig. 1A is an enlarged part of Fig. 1 showing the most important details, Fig. 2 is a cross-sectional view along the line II-II in Fig. 1, Figs. 3 and 4 in a front view and a cross-sectional view, respectively, schematically illustrate a second embodiment of the invention, and Figs. 5 and 6 in a front view and a cross-sectional view, respectively, schematically illustrate a third embodiment of the invention.
- The embodiment shown in Figs. 1, 1A and 2 is described in most detail due to its many advantages, whereas the two alternative embodiments according to Figs. 3-6 are more briefly dealt with towards the end of the description. For a full understanding of the two alternative embodiments reference is also being made to Figs. 1, 1A and 2 with accompanying description.
- A combined rail vehicle brake unit and spring brake actuator is shown in Fig. 1.
- A brake piston 1 is axially movable in a brake unit cylinder comprising a
housing 2 and abottom 3. A piston return spring 4 is as usual arranged between the piston 1 and thebottom 3. A tube-shaped,stationary member 5 is integral with thebottom 3 and houses a slack adjuster (not shown) of any conventional kind. An outgoing force-transmittingpart 6 may be regarded as connected to the piston 1. - A spring brake actuator is combined with the brake unit so far described. The actuator has a cylinder-shaped housing 7 provided with
brackets 8 for the mounting of the combined brake unit and actuator to a suitable part of a rail vehicle underframe (not shown). The twohousings 2 and 7 are firmly joined together and with thebottom 3 in a conventional way not described. Apiston 9 with apiston rod 10 is axially movable in the cylinder- shaped housing 7. Thepiston 9 is provided with a sealing 11, and a further sealing 12 is arranged in the housing 7 against thepiston rod 10. Aforceful compression spring 13 of the helical type is arranged around thepiston rod 10 between the housing 7 and a flange 10ʹ on thepiston rod 10. - The
piston rod 10 is tubular and slidable on the cylindrical,stationary member 5. In order to transmit spring brake forces (for parking and emergency braking) from thecompression spring 13 to the outgoing force-transmittingpart 6 via thepiston rod 10 there is provided an arrangement, most clearly shown to a larger scale in Fig. 1A: Apiston rod sleeve 14 is normally functionally connected to thepiston rod 10 by means of aresilient locking ring 15 in twoannular grooves piston rod 10 and thesleeve 14, respectively. The function of thelocking ring 15 will be described in further detail below. Thesleeve 14 is partly guided for axial movements on thestationary member 5 but also within thepiston rod 10. The force from thespring 13 transferred via thepiston rod 10, thelocking ring 15 and thepiston rod sleeve 14 is transmitted to the force-transmittingpart 6 by means of aspring ring 18 arranged in an annular groove in thepart 6. - The intrusion of moisture, dirt and the like is effectively prevented by a
bellows 19 covering the whole mechanism from the force-transmittingpart 6 to the left in Fig. 1 to the actuator housing 7. - In Fig. 1 both the brake unit and the spring brake actuator are shown in their respective inactive conditions. For the spring brake actuator this means that the
spring 13 is held compressed by brake fluid pressure acting to the right in Fig. 1 on thepiston 9. It is obvious that if this fluid pressure is lowered, the force of thespring 13 will act on the outgoing force-transmittingpart 6 via thespring ring 18, provided that thelocking ring 15 is in its shown position axially locking the twomembers spring ring 18 the brake unit itself can apply a brake force (by fluid pressure acting on the piston 1) via the force-transmittingpart 6 without involving the spring brake actuator. - The
locking ring 15 is slitted (or in other words of the circlip type), as appears in Fig. 2, and can be forced to expand radially from its rest position shown in Figs. 1 and 2. This expanding force is accomplished by a tapered side surface cooperating with a corresponding tapered side surface of thegroove 17 as most clearly shown in Fig. 1A. The depth of thegroove 16 in thepiston rod 10 is at least as great as the thickness or height of thelocking ring 15. Accordingly the ring 15 - if forced and allowed to expand - can be fully accomodated in said groove unlocking the connection with thepiston rod sleeve 14, which thus can move independently of thepiston rod 10. - At either side of its slit the
locking ring 15 is provided with a head 15ʹ having an oblique or wedge-shaped external surface. The heads 15ʹ extend into a compartment 20 in the piston rod flange 10ʹ. Alocking yoke 21 is arranged in this compartment 20 as well as alocking cube 22 above the yoke against the top wall of the compartment. The upper surface of theyoke 21 and the lower surface of thecube 22 are correspondingly oblique or wedge-shaped, as most clearly appears in Fig. 3. The wedge angle is comparatively small, as will be further described below. As shown in Fig. 2, the total height of the compartment 20 is such that the yoke 21 - having inner surfaces conforming to the outer surfaces of the locking ring heads 15ʹ - is held down over the heads, when thecube 22 is right over the yoke as illustrated. - By the provision of a groove and pin arrangement (not shown) the
yoke 21 is guided for movements radially relative to thelocking ring 15. As appears from Fig. 2, thecube 22 is movable perpendicularly thereto and is attached to acontrol rod 23 extending out of the piston rod flange 10ʹ, in which it is situated. In an oblong hole in the end of the rod 23 a ring-shaped control lever 24 is attached. By this arrangement, thecontrol rod 23 and thus thelocking cube 22 can be moved to the right in Fig. 2 by depressing thecontrol lever 24, so that thelocking yoke 21 can move radially upwards in the compartment 20 leaving its engagement with the locking ring heads 15ʹ. Hereby thelocking ring 15 can be forced to expand radially into thepiston rod groove 16 by its tapered side, thus allowing free relative axial movements between thepiston rod 10 and thepiston rod sleeve 14, which otherwise are locked together by thelocking ring 15. - A
return spring 25 of the helical compression type is arranged around thecontrol rod 23 and exerts a biasing force to the left in Fig. 2 on the lockingcube 22 for again placing it in locking position above the lockingyoke 21. - Briefly stated, the aim of the mechanism having as its main component the locking
ring 15 controlled by the parts 21-25 is to allow a discontinuation of the force transmission from thespring 13 to thepart 6 via thesleeve 14 in spite of the fact that there is no fluid pressure available for compressing thespring 13 by pushing thespring brake piston 9 to the right in Fig.1. Typically, such a situation occurs when worn-out brake pads shall be replaced or when a parking braked vehicle equipped with a brake unit integrated with a spring brake actuator as shown in Fig. 1 is to be moved in the absence of brake fluid pressure. In such a case it is only necessary to manually push down thelever 24 so as to allow thelocking ring 15 to be expanded into thegroove 16 and thesleeve 14 together with thepart 6 to be unloaded from the parking brake force of thespring 13. In this unloaded condition of the unit the return spring 4 is able to fully retract the brake unit piston 1 to the position to the left against the bottom of the actuator housing 7. - At the return of fluid pressure acting on the
spring brake piston 9 thespring 13 will again be compressed. When the twogrooves piston rod 10 and thepiston rod sleeve 14, respectively, are again facing each other, the lockingring 15 will spring down in itsgroove 17. Thereturn spring 25 pushes the lockingcube 22 to the left in Fig. 2 thereby pushing down the lockingyoke 21 into its locking position over the locking ring heads 15ʹ as shown in Fig. 2. For this purpose the lockingcube 22 and the lockingyoke 21 have cooperating bevelled or slanted surfaces. When the different parts have re-assumed their positions shown in Fig. 2 (and Fig. 1), the working function of the unit has been restored, and it is important to notice that this restoration is completely automatic. - Besides the two basic requirements for the arrangement, namely to guarantee locking under normal circumstances (by the
cube 22 and yoke 21) and automatic restoration of the working function after unlocking, an obvious requirement is that the manual release or unlocking can be performed with moderate effort. In a practial case the limit for the necessary pulling force in thecontrol rod 23 in order to obtain manual release has been set to 200 N (including the counter-acting force of the return spring 25) at a parking brake force (force of the spring 13) of 25 000 N. It has been determined that this requirement can be safely met, as long as the friction coefficient within the arrangement is normal, i.e. below say 0.25. - As appears from the description above of the arrangement, the reaction force from the
spring 13 is reduced in four steps to the desired low pulling force in thecontrol rod 23; three of these steps are based on wedge action. Step 1 is the transformation of the axial force from thespring 13 acting on the lockingring 15 to a reduced radial force through the locking ring wedge surface.Step 2 is the transformation of the radial force in the lockingring 15 to a tangential force in the locking ring heads 15ʹ; the force reduction obtained is constant and only depending on the geometrical relations.Step 3 is the transformation of the tangential force to a radial force on the lockingyoke 21 obtained through the cooperating outer and inner surfaces, respectively, in the heads 15ʹ and in theyoke 21. Step 4 is the transformation of the force in the radial or upwards direction in theyoke 21 to an axial force in thecontrol rod 23 by the cooperating sloping surfaces on top of theyoke 21 and on the lower side of the lockingcube 22, respectively. - The embodiment described above is the preferred one, but several other embodiments within the general inventive concept are feasible. Two such embodiments are illustrated in Figs. 3 and 4 and Figs. 5 and 6 respectively.
- In the embodiment according to Figs. 3 and 4 a locking ring 30 (completely corresponding to the locking
ring 15 in the first embodiment) is arranged in twocircumferential grooves brake actuator parts ring 30 is slitted and has a bias to the position shown in Figs. 3 and 4. By a wedged side it will be subjected to a force biasing it radially into thegroove 31 in thepart 33 if not held in position. This is performed by acircumferential control latch 35, which is pivotally mounted at a fixedpoint 36. The pivotal movement in the direction of the arrow in Fig. 3 is limited by a fixedpin 37 and a corresponding recess in thelatch 35. Two notches are provided in the latch 35: a first one for afirst head 38 on the latch and a second one for asecond head 39 thereon. Thefirst head 38 is big enough never to leave its latch notch, when thelatch 35 is manually transferred in the direction of the arrow, whereas thesecond head 39 in the corresponding situation will be free from thelatch 35, so that the lockingring 30 can expand radially into thegroove 31 and setparts ring 30 will be restored automatically, provided that a return spring force is exerted on the lockingring 35 in the clockwise direction as viewed in Fig. 3. - The basic principle of the embodiment according to Figs. 5 and 6 is the same as that of the two previous ones with the slight difference that in this case a
circumferential locking ring 40 is biassed radially inwards from its normal condition as shown in Figs. 5 and 6, if acontrol slide 41 is manually pulled in the direction of the arrow in Fig. 5, so that the narrow part of the slide comes between the ends of theslitted ring 40. This means that the lockingring 40 in its unlocked condition will rest in acircumferential groove 42 in a spring brake actuator part 43 that is coaxially within anotherpart 44. Also in this case thecontrol slide 41 must be returned by spring force to its position shown in Fig. 5, in order to automatically restore the operating function of the spring brake actuator. - The spring brake actuator shown and described is combined with a brake unit, but it is to be understood that the invention is equally applicable to a spring brake actuator used alone, also as service brake actuator. The invention is likewise applicable to a spring brake actuator used for other purposes than on rail vehicles.
- In some instances use has been made of expressions such as "upper", "lower" and the like, especially when reference is being made to Fig. 2. However, such expressions are not to be seen as limiting in any way; to the contrary the arrangement can be placed in any position without any drawback as to the proper function.
- Modifications are possible within the scope of the appended claims.
Claims (7)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT87201662T ATE51593T1 (en) | 1986-09-08 | 1987-09-03 | DEVICE ON A SPRING BRAKE. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE8603745A SE454428B (en) | 1986-09-08 | 1986-09-08 | LOADING DEVICE IN SPRING BRAKE ACTUATOR TO CANCEL AND AUTOMATICALLY RETURN THE WORK FUNCTION |
SE8603745 | 1986-09-08 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0259924A2 true EP0259924A2 (en) | 1988-03-16 |
EP0259924A3 EP0259924A3 (en) | 1988-09-07 |
EP0259924B1 EP0259924B1 (en) | 1990-04-04 |
Family
ID=20365510
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP87201662A Expired - Lifetime EP0259924B1 (en) | 1986-09-08 | 1987-09-03 | A device at a spring brake actuator |
Country Status (18)
Country | Link |
---|---|
US (1) | US4777867A (en) |
EP (1) | EP0259924B1 (en) |
JP (1) | JPH086771B2 (en) |
KR (1) | KR960005844B1 (en) |
CN (1) | CN1010470B (en) |
AT (1) | ATE51593T1 (en) |
AU (1) | AU585171B2 (en) |
BR (1) | BR8704619A (en) |
CA (1) | CA1301082C (en) |
CS (1) | CS274565B2 (en) |
DE (1) | DE3762112D1 (en) |
ES (1) | ES2014021B3 (en) |
HU (1) | HU199736B (en) |
IN (1) | IN169586B (en) |
SE (1) | SE454428B (en) |
SU (1) | SU1508954A3 (en) |
YU (1) | YU46877B (en) |
ZA (1) | ZA876668B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19512997C1 (en) * | 1995-04-06 | 1996-11-07 | Knorr Bremse Systeme | Actuating device for braking devices of rail vehicles |
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US5193431A (en) * | 1989-11-03 | 1993-03-16 | Parker-Hannifin Corporation | Device for operation of a sliding door member |
US5115176A (en) * | 1990-10-22 | 1992-05-19 | White Dewitt T | Control arrangement for electrically propelled wheeled vehicles |
IT1241352B (en) * | 1990-12-13 | 1994-01-10 | Bendix Heavy Vehicle Syst | BRAKING ELEMENT FOR PNEUMATIC BRAKING SYSTEMS |
SE510583C2 (en) * | 1994-10-24 | 1999-06-07 | Sab Wabco Ab | Safety brake arrangement in a brake actuator |
US5937974A (en) | 1997-05-02 | 1999-08-17 | Westinghouse Air Brake Company | Spring applied parking brake actuator having a collet style slack adjuster |
US5848550A (en) * | 1997-05-02 | 1998-12-15 | Westinghouse Air Brake Company | Parking brake manual release mechanism |
US6702072B2 (en) * | 2002-04-18 | 2004-03-09 | Westinghouse Air Brake Technologies Corporation | Brake cylinder unit |
SE523553C2 (en) * | 2002-07-04 | 2004-04-27 | Haldex Brake Prod Ab | Fluid-activated parking brake |
US7140477B2 (en) * | 2003-09-09 | 2006-11-28 | Wabtec Holding Corp. | Automatic parking brake for a rail vehicle |
US7493994B2 (en) * | 2004-12-16 | 2009-02-24 | Bendix Spicer Foundation Brake Llc | Spring brake actuator with mid-located spring |
WO2009144863A1 (en) * | 2008-05-29 | 2009-12-03 | ナブテスコ株式会社 | Brake cylinder apparatus and brake caliper apparatus |
US8082645B2 (en) * | 2008-12-08 | 2011-12-27 | Wabtec Holding Corp. | Rotary manual release |
DE102019113930A1 (en) * | 2019-05-24 | 2020-11-26 | Knorr-Bremse Systeme für Schienenfahrzeuge GmbH | Brake cylinder with a locking device for mechanical braking force locking |
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SE383997B (en) * | 1973-10-25 | 1976-04-12 | Bromsregulator Svenska Ab | LASEN DEVICE FOR SPRING BRAKE ACTUATOR |
DE2328435B2 (en) * | 1972-06-07 | 1978-10-19 | Centralnyj Ordena Trudovogo Krasnogo Znameni Nautschno-Issledovatelskij Avtomobilnyj I Avtomotornyj Institut, Moskau | Release device for the spring brake of a combined service brake and spring brake cylinder |
EP0073549A1 (en) * | 1979-03-06 | 1983-03-09 | Bendix Limited | Spring force applying actuators |
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US3070389A (en) * | 1956-09-14 | 1962-12-25 | Agfa Ag Fa | Structure for removable connecting a device to a support therefor |
DE1083675B (en) * | 1958-07-19 | 1960-06-15 | Zahnradfabrik Friedrichshafen | Steering lock for motor vehicles, especially for farm tractors and tractors |
US3994206A (en) * | 1973-10-25 | 1976-11-30 | Svenska Aktiebolaget Bromsregulator | Device for discontinuing and automatically restoring the operational function of a spring brake actuator |
US4036111A (en) * | 1973-10-25 | 1977-07-19 | Svenska Aktiebolaget Bromsregulator | Device for discontinuing and automatically restoring the operational function of a spring brake actuator |
US3918346A (en) * | 1974-07-11 | 1975-11-11 | Us Army | Frictional lock for retaining a rotatable piston against axial displacement |
SE392436B (en) * | 1975-03-03 | 1977-03-28 | Bromsregulator Svenska Ab | DEVICE FOR CANCELING AND AUTOMATICALLY RESTORING THE WORKING FUNCTION OF A SPRING BRAKE ACTUATOR |
SE402081B (en) * | 1976-10-11 | 1978-06-19 | Bromsregulator Svenska Ab | DEVICE WITH CONTROL VALVE TO CANCEL AND RESTORE THE WORKING FUNCTION OF A SPRING BRAKE ACTUATOR |
DE2646158C2 (en) * | 1976-10-13 | 1978-12-07 | Graubremse Gmbh, 6900 Heidelberg | Quickly releasable spring force storage device, especially for parking brakes of motor vehicles |
DE2800449C3 (en) * | 1978-01-05 | 1980-12-04 | Knorr-Bremse Gmbh, 8000 Muenchen | Snap release device for spring brake cylinders with damping device |
DE2952205A1 (en) * | 1979-12-22 | 1981-06-25 | Knorr-Bremse GmbH, 8000 München | SPRING-BRAKE CYLINDER |
US4364305A (en) * | 1980-06-09 | 1982-12-21 | Wabco Westinghouse, S.A. | Brake cylinder device combining a pneumatically-applied service brake and a spring-applied parking brake |
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US4552056A (en) * | 1984-12-24 | 1985-11-12 | Wabco Ltd. | Manual release and automatic reset arrangement for spring-applied/air-released brake |
-
1986
- 1986-09-08 SE SE8603745A patent/SE454428B/en not_active IP Right Cessation
-
1987
- 1987-08-25 IN IN753/DEL/87A patent/IN169586B/en unknown
- 1987-08-27 US US07/089,851 patent/US4777867A/en not_active Expired - Lifetime
- 1987-09-03 ES ES87201662T patent/ES2014021B3/en not_active Expired - Lifetime
- 1987-09-03 AT AT87201662T patent/ATE51593T1/en not_active IP Right Cessation
- 1987-09-03 EP EP87201662A patent/EP0259924B1/en not_active Expired - Lifetime
- 1987-09-03 DE DE8787201662T patent/DE3762112D1/en not_active Expired - Lifetime
- 1987-09-04 BR BR8704619A patent/BR8704619A/en not_active IP Right Cessation
- 1987-09-04 CA CA000546185A patent/CA1301082C/en not_active Expired - Fee Related
- 1987-09-07 HU HU873987A patent/HU199736B/en not_active IP Right Cessation
- 1987-09-07 ZA ZA876668A patent/ZA876668B/en unknown
- 1987-09-07 SU SU874203363A patent/SU1508954A3/en active
- 1987-09-08 KR KR1019870009905A patent/KR960005844B1/en not_active IP Right Cessation
- 1987-09-08 JP JP62223198A patent/JPH086771B2/en not_active Expired - Lifetime
- 1987-09-08 CS CS649887A patent/CS274565B2/en not_active IP Right Cessation
- 1987-09-08 CN CN87106191A patent/CN1010470B/en not_active Expired
- 1987-09-08 AU AU78163/87A patent/AU585171B2/en not_active Ceased
- 1987-09-08 YU YU166887A patent/YU46877B/en unknown
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DE2328435B2 (en) * | 1972-06-07 | 1978-10-19 | Centralnyj Ordena Trudovogo Krasnogo Znameni Nautschno-Issledovatelskij Avtomobilnyj I Avtomotornyj Institut, Moskau | Release device for the spring brake of a combined service brake and spring brake cylinder |
SE383997B (en) * | 1973-10-25 | 1976-04-12 | Bromsregulator Svenska Ab | LASEN DEVICE FOR SPRING BRAKE ACTUATOR |
EP0073549A1 (en) * | 1979-03-06 | 1983-03-09 | Bendix Limited | Spring force applying actuators |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19512997C1 (en) * | 1995-04-06 | 1996-11-07 | Knorr Bremse Systeme | Actuating device for braking devices of rail vehicles |
Also Published As
Publication number | Publication date |
---|---|
AU7816387A (en) | 1988-03-10 |
YU166887A (en) | 1990-02-28 |
KR880004249A (en) | 1988-06-07 |
CS274565B2 (en) | 1991-08-13 |
ATE51593T1 (en) | 1990-04-15 |
EP0259924A3 (en) | 1988-09-07 |
AU585171B2 (en) | 1989-06-08 |
SE454428B (en) | 1988-05-02 |
CA1301082C (en) | 1992-05-19 |
HU199736B (en) | 1990-03-28 |
CS649887A2 (en) | 1990-12-13 |
YU46877B (en) | 1994-06-24 |
CN87106191A (en) | 1988-06-22 |
HUT47058A (en) | 1989-01-30 |
IN169586B (en) | 1991-11-16 |
CN1010470B (en) | 1990-11-21 |
BR8704619A (en) | 1988-04-26 |
SE8603745L (en) | 1988-03-09 |
DE3762112D1 (en) | 1990-05-10 |
SU1508954A3 (en) | 1989-09-15 |
ZA876668B (en) | 1988-03-07 |
ES2014021B3 (en) | 1990-06-16 |
US4777867A (en) | 1988-10-18 |
KR960005844B1 (en) | 1996-05-03 |
JPS6372926A (en) | 1988-04-02 |
SE8603745D0 (en) | 1986-09-08 |
EP0259924B1 (en) | 1990-04-04 |
JPH086771B2 (en) | 1996-01-29 |
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